Spark timing indicator



June 3, 1958 SCHOENLEBER 2,837,713

SPARK TIMING INDICATOR Filed Dec. 30. 1952 I N VEN TOR. [IWfl CE MSEl/OENLEJEZ tates Unite SPARK TIMING mmcA'ron Application December 30, 1952, Serial No. 328,630

10 Claims. (Cl. 324-16) The present invention relates to a spark timing indicator and it is a primary object of the present invention to improve the operation and construction of indicators of this class. A further object of the present invention is to provide an indicating mechanism for accurately indicating the timing of the ignition spark with respect to the position of the piston while the engine is running, and which reading is clearly visible to the operator.

Other objects and advantages of the'present invention will readily appear to those familiar with the art "after a perusal of the following specification and drawings.

In the drawings:

Fig. l is a right-side elevational view of an engine shown in combination with a spark timing indicator illustrative of the present invention, a portion of the engine being broken away to show details in construction thereof.

Fig. 2 is a front view of the combination shown in Fig. 1. i

Fig. 3 is an exploded perspective view of the spark timing indicator shown in Fig. 1.

Fig. 4'is a fragmentary view of an engine in combination with a spark timing indicator showing a modification of the present invention.

Referring to Figs. 1 and2 of the drawings, my invention is shown in "combination with an internal combustion multi-cylinder engine, generally designated by the number 10, which can be of any suitable or well-known construction, and the number 11 represents a plurality of pistons of the engine 10 which are each connected by the usual connecting rod 12 to a crank shaft 13. The engine 10 in the present instance employs a magneto 14 which is driven from the crank shaft 13 of the engine in any well-known manner, and a distributing head 15 carried adjacent one end of the magneto 14 successively electrifies a plurality of spark plugs 16 which are in association with the respective pistons 11 as well-known in the art, the distributing head 15 being connected to the spark plugs 16 by suitable electrical connecting wires 17. At the front of the engine 19 is rotatably carried a fan 18 of any well-known or suitable type which is drivingly connected to a driven pulley 19. A driving pulley 20 is drivingly carried on that portion of the crank shaft 13 extending forwardly of the engineltl, and the driving pulley 24) is positioned in alignment with respect to the driven pulley 19, afan belt 21 drivingly connecting these pulleysso that the fan 18 is drivingly connected to the crank shaft 13. It will be appreciated that the above described structures or mechanisms are well-known in the art and are capable of being of any well-known or.

suitable construction.

The indexing mechanism of'the present invention is designated generally bythe number 22, see also Fig. 3, and comprises apointer 23. secured to the driving pulley 20 by means of suitable cap screws or the like 24. The pointer-23 is preferably secured near the outer periphery of the driving pulley 20 and a dial 25 is so shaped and carried'a's tobe positioned in close proximity to the path tent "ice of travel of a point 25a of the pointer 23 when the engine 10 is in operation. The pointer 23 and the dial 25 are each formed of a metal which has a good electrical conducting characteristic. More specifically the dial 25 is secured by means of suitable cap screws or the like 26 to a block of non-conducting material 27, this block being capable of being formed of any suitable substantially rigid material which has non-conducting characteristics, of which many are well known. The block 27-is secured to a suitable supporting bracket 28 as by bolts or the like 29, and the bracket 28 is secured to the face of the engine 10 as by bolt or the like 30. The dial 25 is provided with a suitable scale 31 indicating in degrees or seconds or any other measurement which might be desirably used, the amount of advance, or otherwise, of the ignition spark from the top dead center position of a piston'as will be more fully appreciated hereinafter.

In operation one of the pistons 11, shown in solid lines in Fig. 1, is moved into its top dead center position. The dial 25, which is provided with suitable adjusting slots 32 which receive the cap screws 26, is so adjusted that the point 25a of the pointer 23 coincides with one of the indexing marks on the scale 31, preferably the mark identified as 0. Upon the dial being properly adjusted, the cap screws 26 are tightened sufiiciently to hold the dial 25 against displacement out of its adjusted position. The dial 25 is then successively electrified by connecting the spark plug wire 17, connecting the magneto 14 to that particular piston 11 which in top dead center position, to the dial 25 by means of a suitable interconnecting electrical connecting wire 31a. In the operation of the engine the dial 25 is successively electrified by the magneto 14, and a spark will occur between the dial 25 and point 25a of the pointer 23 at the point on the dial at which the point 25a happens to be when the spark occurs. This spark can be readily observed and indicates by its relationship to the indexing mark previously observed when the piston was at top dead center position the degrees of advance or retard of the spark. It will be appreciated that any necessary corrections which must be made in the ignition system can now be readily made and the results thereof checked. i

If it is desired that the readings be made without shorting out one of the spark plugs of the engine, an inductance coil 33 can be positioned around the wire 17 adjacent the particular spark plug 16 associated with the piston 11 which is at its top dead center position, see Fig. 4. This inductance coil 33 is connected to the dial 25 by means of an electrical connecting wire 34 so that upon operation of the engine 10, the dial 25 will be electrified suiticiently by induction to cause a spark between the dial and the point 25a of the pointer 23 when this particular plug 16 is electrified by the magneto 14. The degree of advance, or otherwise, of the ignition spark can therefore be observed in the same manner as previously described except that in this embodiment the spark plug is not shorted out.

The advantages of a device of this type are, first, its extreme simplicity, and second, the ease of making the observations as compared, for example, with observing fly wheel marking by means of a neon timing light.

I claim:

1. Means for timing the ignition in an internal combustion engine of the type having a fan belt pulley adapted to be moved in synchronism with the crank shaft, a pointer carried by the pulley and formed of conducting material, a dial of conducting material carried adjacent said pulley and in close proximity to the path of travel of said pointer, said dial being insulated from said engine and said pulley and having formed thereon an indexing mark adapted to coincide with said pointer when a piston of said engine is at top dead center, and an electrical connection between the ignition system and said dial for electrifying said dial when a'spark would normally occur with respect to said top dead center piston so that, a spark occurs between said dial and said pointer, enabling thereby the advance or retard of said spark to be observed in relationship to said indexing mark while the engine is running. r

2. Means for timing the ignition in an internal combustion engine of the type having a fan belt pulley adapted to be moved in synchronism with the crank shaft, a pointer carried by the pulley and formed of conducting ,material, a dial of conducting material carried adjacent said pulley and in close proximity to the path of travel of said pointer, said dial being insulated from said engine and said pulley and having formed thereon an indexing mark adapted to coincide with said pointer when a piston of said engine is at top dead center, and means for electrifying said dial by inductance from the ignition system so that a spark occurs between said dial and said pointer when the spark plug associated with said top dead center piston is sparked, enabling thereby the advance or retard of the first mentioned spark to be observed in relationship to said indexing mark while the engine is running.

3. In an internal combustion engine having power responsive pistons, a spark ignition system, and a fan-belt pulley, a spark timing indicator for indicating the timing of the spark ignition system in relation to the rotation of the fan-belt pulley, said indicator including a pointer formed of conducting material and carried by said fanbelt pulley adjacent the periphery thereof, a dial while the engine is running carried adjacent said pulley and nonrotatable with respect thereto, said dial being positioned in close proximity to the path of travel of said pointer, said dial being insulated from said engine and having formed thereon an index mark which coincides with said pointer upon one of said pistons being positioned on top dead center, and means interconnecting said spark ignition system and said dial for electrifying said dial so that a spark occurs between said dial and said pointer when a spark would normally occur with respect to said top centered piston enabling thereby the advance or retard of the ignition system to be observed upon said dial while the engine is running.

4. In an internal combustion engine having power responsive pistons, a spark ignition system, and a fan-belt pulley, a spark timing indicator for indicating the timing of the spark ignition system in relation to the rotation of the fan-belt pulley, said indicator including a pointer formed of conducting material and carried by said fanbelt pulley adjacent the periphery thereof, a dial of conducting material carried adjacent said pulley and nonrotatable with respect thereto, said dial being positioned in close proximity to the path of travel of said pointer, said dial being insulated from said engine and having formed thereon an index mark which coincides with said pointer upon one of said pistons being positioned on top dead center, and means interconnecting said spark ignition system and said dial for electrifying said dial by inductance so that a spark occurs between said dial and said pointer when a spark normally occurs with respect to said top centered piston enabling thereby the advance or retard of the ignition system to be observed upon said dial while the engine is running.

5. Means for timing the ignition in an internal combustion engine of the type having a fan belt pulley adapted to be moved in synchronism with the crank shaft, a pointer carried by said pulley and formed of conducting material and positioned near the outer periphery of the pulley, a part circular shaped dial formed of conducting material and having formed thereon a scale, mounting means for supporting said dial from said engine in close proximity to the path of travel of said pointer so that said pointer is in indicating relationship with respect to said scale, said dial being insulated-from said mounting 4 means and said mounting means being adapted to provide angular adjustment of said dial so that an indexing mark on said scale can be moved to coincide with said pointer when a piston of said engine is at top dead center, and an electrical connection between the ignition system and said dial for electrifying said dial when a spark would normally occur with respect to said top dead center piston so that a spark occurs between said dial and said pointer at a point on the dial opposite which the pointer happens to be when the spark occurs, enabling thereby the advance or retard of said spark to be observed in relation to said indexing mark while said engine is running.

6. Means for. timing the ignition in an internal combustion engine of the type having a fan belt pulley adapted to be moved in synchronism with the crank shaft, a pointer carried by said pulley and formed of conducting material and positioned near the outer periphery of the pulley, a part circular shaped dial formed of conducting material and having formed thereon a scale, mounting means for supporting said dial from said engine in close proximity to the path of travel of said pointer so that said pointer is in indicating relationship with respect to said scale, said dial being insulated from said mounting means and said mounting means permitting angular adjustment of said dial so that an indexing mark on said scale can be moved to coincide with said pointer when a piston of said engine is at top dead center, and an electrical connection between the spark plug associated with said top dead center piston and said dial for electrifying said dial by inductance when a spark normally occurs with respect to said top dead center piston so that a spark occurs between said dial and said pointer at a point on the dial opposite which the pointer happens to be when the second mentioned spark occurs, enabling thereby the advance or retard of said second mentioned spark to be observed in relation to said indexing mark during the operation of said engine.

7. In an engine having a piston, a spark plug, an ignition system for supplying an electrical impulse to said spark plug in accordance with the cycle of said piston, and a fan belt pulley, a spark indicating mechanism comprising a pointer carried by said fan belt pulley, said pointer being formed of conducting material, a dial carried adjacent said pulley and nonrotatable with respect thereto and being in close proximity to said pointer upon said pointer being revolved by said pulley, said dial having an index formed thereon which is in alignment with said pointer when said piston is in its upper dead center position, and means for electrifying said dial by inductance from said spark plug so that a spark occurs between said dial and said pointer when said spark plug is sparked by said ignition system, enabling thereby the advance or retard of said spark to be observed upon said dial during the operation of said engine.

8. Means for observing the spark timing during the operation of an internal combustion engine having a frame, a reciprocating piston, a rotating crank shaft, a spark plug and an ignition system constituted to produce sparks at said spark plug in timed relation to the movements of said piston, said means including a pointer of electrically conductive material fixed in relation to said crankshaft so as to describe a circle thereabout, an electrically conductive dial insulatedly fixed in relation to said frame in proximity to the circle described by said pointer, graduations on said dial registering with said pointer to indicate positions of said crankshaft and piston and an electrical connection between said spark plug and said dial for causing a spark to jump between said dial and said pointer to indicate by its position relatively to said graduations, the position attained by said piston and crankshaft when a spark occurs at said spark plug.

9. Means for observing the spark timing during the operation of an internal combustion engine having a frame, a reciprocating piston, a rotating crankshaft, a

belt pulley fixed in relation to said crankshaft, a spark plug associated with said cylinder for igniting charges therein, and an ignition system constituted to produce sparks at said spark plug in timed relation to the movements of said piston and crankshaft and including a wire leading to said spark plug, said means including a pointer of electrically conductive material fixed on said pulley, so as to describe a circle about said crankshaft, an electrically conductive dial insulatedly fixed on said frame in proximity to the circle described by said pointer, graduations on said dial registering with said pointer to indicate positions of said crankshaft and piston and means for connecting said wire to said dial in lieu of said spark plug for causing a spark to jump between said dial and said pointer to indicate by its position relatively to said graduations the position attained by said piston and crankshaft when a spark would occur at said spark plug.

10. Means for observing the spark timing during the operation of an internal combustion engine having a frame, a reciprocating piston, a rotating crankshaft, a belt pulley fixed in relation to said crankshaft, a spark plug associated with said cylinder for .igniting charges therein, and an ignition system constituted to produce sparks at said spark plug in timed relation to the movements of said piston and crankshaft and including a wire leading to said spark plug, said means including a pointer of electrically conductive material fixed on said pulley, so as to describe a circle about said crankshaft, an electrically conductive dial insulatedly fixed on said frame in proximity to the circle described by said pointer, graduations on said dial registering with said pointer to indicate positions of said crankshaft and piston, an induction member disposed in proximity to said wire so as to receive an impulse therefrom Whenever a spark is produced at said plug, and a wire leading from said induction member and connected with said dial for transmitting said impulse to said dial, and said induction member being so proportioned asto cause a spark to jump between said dial and said pointer to indicate by its position relatively to said graduations the position attained by said piston and crankshaft when a spark occurs at said spark plug.

References Cited in the file of this patent UNITED STATES PATENTS Rider Oct. 28, 

